COUNT=0
while COUNT<3:
    USER_NAME=input('>>>Please enter your username:')
    USER_PASSWORD=input('>>>Please enter your password:')
    if USER_NAME=='CLF' and USER_PASSWORD=='clf123':
        print('''\
        Login success!
        welcome
        CLF''')  
        break
    else:
        COUNT+=1
        print('Username or password is incorrect')  
        if COUNT==3:
            print('Error:The number of errors exceeds the limit')
